1. Field of the Invention
This invention relates to an apparatus for weighing a luggage bag and, more particularly, to such an apparatus incorporated within a handle of the luggage bag.
2. Summary of the Background Information
Since most airlines within the United States and other countries now charge substantial fees for overweight luggage, there is a great need for a portable scale for weighing luggage bags. While it is often easy enough to weigh luggage bags at home on a bathroom scale before leaving for an airport, it is generally difficult to find a scale suitable for this purpose after leaving home, so that luggage bags to be carried on return or continuing flights, often filled with additional items purchased during a trip, are weighed for the first time on the scale at an airport ticket counter. At this point, with a tight schedule to reach a departing flight and a long line of passengers waiting to check baggage, it is particularly difficult to rearrange items in luggage to be checked or carried to eliminate or minimize fees for excess baggage weight.
The patent literature includes a number of descriptions of portable devices for weighing luggage bags. For example, a scale including a digital readout is built into a separate handle from which a hook-shaped cradle descends. The handle of a bag to be weighed is placed in the cradle to be lifted for weighing. In another device, an electronic, mechanical, or strain gauge weight sensing system is held under the handle of the luggage bag, with a weight being displayed by an LED device as the bag is lifted. In yet another device, a scale is built into the luggage bag, using an electrical signal derived from a strain gauge mounted at the center of a plate within the carrying case of the bag, with a handle outside the carrying case being attached to each end of the plate, and with the weight of the bag being digitally displayed on the handle.
Other weighing devices are incorporated entirely into the handles of luggage bags. One method for doing this includes a flexible resistance element mounted within the handle to bend as the bag is lifted, and a mechanism for determining the weight of the bag from the flexure of the resistance element, with the weight being digitally displayed on the handle. Other bag handles include built-in weighing devices that measure the forces provided by the attachment of the carrying case at each end of the handle. A problem with using the handle in this way arises from the fact that the total weight of the bag must be derived as the sum of two inputs by summing electrical signals or by connecting springs so that an output point is moved through a distance according to input forces occurring at two separate points.
What is needed is a simple mechanism for determining the weight of a luggage bag from an input force at each end of a handle, without incurring the expense of the transducers and circuitry needed to provide and analyze electrical input signals.